THE OBJECTIVES OF THIS PROPOSED RESEARCH ARE: 1. To measure acid phosphatase, alkaline phosphatase activities and isoenzymes of alkaline phosphatase in the sera of prostatic cancer patients who are in the Chemotherapy Trials of the National Prostatic Cancer Project. 2. To offer an uniform laboratory results for inter-institutional comparison of serum acid phosphatase, alkaline phosphatase activities and its isoenzyme with patients clinical information, and to monitor the efficacy of chemotherapy.